This invention relates to a manually operated control device and an associated method. More particularly, this invention relates to a hand-held, finger and palm operated control device and an associated method.
In the medical and dental fields, a health care professional is frequently required to exercise personal control over a number of operating parameters. Although medical and dental instrument are, in many cases, provided with integral finger operated controls, ancillary equipment is frequently used which requires a control separate from the medical or dental instrument. This control has traditionally been provided by means of a foot switch. However, foot switches have very significant limitations. The user is required to stand or sit in an unbalanced position, which is tiring and burdensome. Moreover, the controlling foot tires and may fall and inadvertently actuate the foot switch. Where the user has lost track of the foot switch, he or she must divert their attention away from the patient and the operating instruments to locate the misplaced foot switch. This diversion of attention can lead to inefficiency, loss of concentration and even to accidents, as well. In addition, the cords extending to the foot switch are generally strewn across the floor, provided a hazard to effective negotiation of the floor surface.
A conventional alternative to the foot switch is the assistant. An assistant is disadvantageous for several reasons. The assistant must be told what to do, so there is inevitably a delay between the necessity for action as perceived by the surgeon, doctor or dentist and the completed action as carried out by the assistant. Assistants can fail to properly attend to the ongoing operation and thus be the source of accidents. Assistants take up space in the operating room or dental office. Last but not least, assistants are expensive.
Many proposals have been advanced for attaching switches to the hand. Most such proposals contemplate attaching a switch to the back of the hand. U.S. Pat. No. 3,700,835 to Rackson, however, discloses a hand held, finger controlled switch device which sits on the palm of the user and is connected to a selected nonindex finger of the user via a ring or loop. The switch has upwardly projecting switch levers which are actuated by touch of the finger tips. A wire extends from the switch device and the user's palm in a direction opposite to the base of the thumb. The design enables the user to hold and actuate the switch, while simultaneously permitting the user to use the first two or three fingers. The disadvantages of this configuration, however, soon become apparent. The switch tends to rotate on the user's palm about the selected finger. Because the switch is activated by the finger tips, any rotation is critical. Rotation displaces the switch levers, causing the user to press a wrong button or to divert his attention to looking for the position of the control device and to shifting the device back into place relative to the fingers. This problem is recognized by Rackson, and elaborate means to overcome this limitation are disclosed by him. These means include the above-mentioned ring-like structure common to all the disclosed switched and additional designs with finger enclosures that hold the device in place relative to the finger tips. A further solution to this problem is disclosed in U.S. Pat. No. 3,700,836 to Rackson. In accordance with that solution, the switching device is fastened to the user's palm via a glove, a wrist brace or other kind of bracket.
The control device attached to the hand via a glove or a wrist brace as disclosed in U.S. Pat. No. 3,700,836 is burdensome to a medical or dental practitioner. A glove or a wrist brace restricts the hand and can interfere with conventional medical and dental procedures.
Thus, the prior art discloses a hand-held switch that is activated by several fingers, leaving at least the thumb and the index finger free for use. The prior art fails, however, to propose or suggest a structure for this function that can be comfortably held and actuated in the hand, yet without restrictive and complex wrist, hand and finger attachments. Indeed, the prior art indicates that the effective use of such a switch requires one or more of these cumbersome means so that the switch may be accurately and continuously held in place in the palm of the hand, without inadvertent movement that would preclude its proper function. Considering these insurmountable limitations in the Rackson design and the necessary trade-off that the user must make, there is little wonder why these switches are not in medical or other known use today. This is despite the significant benefits of a switch that permits a single hand to perform dual functions. Certainly, if a simpler and more elegant design solution was thought to exist, it would have been enthusiastically adopted.